olds 307 and 403

Just curious what the tallest, doesn't have to be a wide tire to fit on the back without rubbing issues with stuff in the trunk.

oldsmobiledave

28" tall tire fits no problem. 275 60 15 on 15 x 8" with 4.5" BS. Zero rubbing.


I know you can fit bigger but usually that means going to DOT drag radials or slicks. Clearly not for a daily driver.


Do you really need something taller/bigger than a 275 60 15?

olds 307 and 403

Thinking either 235/75R15 or 255/70R15, if possible to make the 3 spd auto more highway friendly.

oldsmobiledave

235 75 15s are a 73-87 square body truck tire. Don't use that size.


I have seen others run the 255 70 15s. They are tall. You will need a very tall front tire unless you like the steam roller look.

olds 307 and 403

I would rather use a 255/70R15. I would use a 215/75R14 tire up front. I found a 69 Chevelle picture with them in back, the wheel well looks similar and filled right up. A member on here is using them on his 83 Hurst Olds, less room in the G bodies tire well. There are a few tires available in that size with car style tread. Another option is 30×9.5-15 but most come in truck AT tread.

olds 307 and 403

I found some less agressive tires in the 30×9.5-15 tires, like a car tire tread for a reasonable price. If a 30" tall tire can fit, I would consider them. Going from the current 215/75R14 tires to a 30" tire would reduce highway rpm by 300. Even the 255/70R15 will lower rpm by 170, a good amount and fill the wheel wells right up.

oldsmobiledave

The front tires are too small. They will only be 26.7" tall compared to 29.1" in the back. On top of that 75 series tires are not known for their handling abilities. Hello steam roller. It will look silly & drive like crap.


Get rid of the front 14" rims. Pick a proper stagger front to back using 4 15" rims & enjoy the stance and handling.


Do it once & do it right.

w30442

70-72's have huge wheel wells and will swallow a big tire. The 295-65 just rub on my tail pipe when turning at the end of the track but other wise good.

olds 307 and 403

I agree on the huge tire wells on the back. There has to be at least 6" of room to the top and I can go considerbly wider than the current 215/75R14 tries. I want at least a 1" shorter tire on the front due the springs having the front sitting higher. I will pick up four 15" steel rims. What size are your front tires? I could not put 245/60R14 or 215/75R14 tires on my G body without rubbing.

oldsmobiledave

225 70 15s front on 15x7" with 4.25" BS

275 60 15s back on 15x8" with 4.50" BS


Both cars have the same size tires & wheels


As a side note the MT is a way better tire than the BFG.

Fun71

This ain't a G Body.
Over the years I have had a lot of different tires on the front of either my 70 Supreme or the 71 convertible:
245-60-14
215-75-15
225-70-15
245-60-15

245-60-15 are currently on my car and others have used 255-60-15 with no issues, but I had slight rubbing issues on my 70 Supreme back in the 80s with that size up front (tire shop mistakenly put one on the right front instead of 245-60-15).

olds 307 and 403

As many have said thw BFG TA's are a so so tire that look good. I had the T/A's on the 70, they handled shitty compared to the current cheap Motomaster AW2 205/75R14 front and whatever brand 215/75R14 tires on the back. And that is 70 and 60 series BFG tires, they should handle better. I may try the Multimile Wild Country less aggressive tire in 30×9.5-15. I have 31×10.5-15 spare tire off my Dakota to see how if that will squeeze in.

oldcutlass

You may get away with the 255-70-15 rear and 225-70-15 front about a 2" difference.

oldsmobiledave

Are you planning a really steep gear swap? If not why in the world are you messing with 30 & 31" tall tires? Your car has 2.78 gears as per your signature.


Seriously the 275 60 15 & the 255 70 15 are the tallest you need. If you are planning to run junk yard steel rims the 275 60 15 will be too wide on the 7" rim. I think the answer for you is the 255 70 15.


Good luck.

olds 307 and 403

I probably will run 255/70R15, more tire choices. Yeah the 225/70R15 is plenty tall up front, all 4 on regular junkyard 15" steel wheels. Fun71, I realize this is not a G body. Even rough regular models are worth money, unlike my G body.

olds 307 and 403

http://www.southernmotors.com/ford_d...asp?CarId=3859
Here is a link to a Chevelle with 255/70R15 tires in back and 215/65R15 which are actually shorter up front that my current 14" tires, I like the look. The wheel wells covering the tires will help with the steam roller look. Believe it or not the current 205/75R14 front, also had all 4 215/75R14 on the 70, both handled better than 205/70R14 front and 235/60R14 BFG TA's on the 70. Yet the TA's seem better on my 88 CSC. And those are much better than 235/60R14 front and 245/60R14 that were also on my 88, go figure. Like I said even a 26.6 tall skinny tire is too tall up front on the 88, rubs in the corners. Hopefully the 225/70R14 will fit fine in the back on the 88. It will put the speedo right on and drop the rpms by 100, with the ignitor 3 module and these taller, skinnier tires will hopefully get 30 mpg Imperial.